1. Field of the Invention
The present invention relates to a hair bleach composition and a hair dye composition which provide less offensive odor; exhibit excellent hair-bleaching power and hair-dyeing power; and exhibit excellent hair-conditioning effect during and after treatment.
2. Background Art
Among hair dyes, there have widely been employed two-composition-type permanent hair dyes formed of a first composition containing an alkali agent and a second composition containing an oxidizing agent. The alkali agent contained in the first composition is incorporated into the composition in order to enhance bleach effect and hair dye effect and activate the action of the oxidizing agent, to thereby promote oxidation-decomposition of melanin granules contained in the hair, leading the hair to a bright color tone. If the hair is bleached or dyed to a bright color tone as compared with the original color, the bleach or dye composition must possess sufficient bleach power, which generally varies depending on the amount of alkali. Thus, in order to bleach or dye the hair to a bright color tone, the alkali agent in particular must be provided in sufficient amount.
Conventionally, ammonia has generally been employed as the alkali agent. However, ammonia disadvantageously provides considerably unpleasant feeling during treatment because of its strongly offensive odor. Particularly, when a liquid composition is used, the ammonia odor generates easily as compared with the case where a cream-type composition is used. This has imposed great limitations on the freedom of perfume-blending into the composition.
To overcome the above problems, approaches using, instead of ammonia, organic amines generating less offensive odor have been employed (for example, see Japanese Patent Application Laid-Open (kokai) Nos. 59-106413, 1-213220, and 5-246827). However, when these approaches are followed, hair cannot be bleached to have a sufficiently bright color tone. In addition, when an organic amine is used in a large amount, problematic stimulation is readily imparted to the scalp because a comparatively high percentage thereof remains. Thus, bleaching of hair to a satisfactory bright color tone has not been attained. Furthermore, when these agents are used in hair treatment, the treated hair is damaged, resulting in hair dryness, loss of silkiness, and poor combing performance, which are also problematic.
In another approach, a portion of ammonia is substituted by another alkali agent having less odor so as to reduce the offensive odor without sacrificing satisfactory bleach effect (for example, see Japanese Patent Application Laid-Open (kokai) Nos. 9-255540, 10-25230, and 10-45547). When this approach is followed, the offensive odor is reduced to a certain extent. However, the problem cannot be solved completely, since ammonia is still required.
Japanese Patent Application Laid-Open (kokai) No. 11-29443 discloses that the combined use of an alkali agent and a type of aromatic alcohol enhances the bleaching effect and reduces the offensive odor. However, also in this case, inclusion of a certain amount of ammonia into the alkali agent is preferred, and the bleaching effect is poor if the ammonia concentration is low.